Apparatus for use in the manufacture of electric storage batteries

ABSTRACT

An apparatus for welding a battery box lid to a battery box, employing a heater for melting portions of the lid between the filling tubes and around the lid. The heater is provided with bores receiving the filling tubes, the bores being substantially larger than the filling tubes and being undercut from the surface of the heater so that the filling tubes are not melted when the portions of the lid adjacent the filling tubes are melted.

Unite tates Patent [191 Sturmey APPARATUS F OR USE lN THE MANUFACTURE OF ELECTRIC STORAGE BATTERKES [75] Inventor: Kenelm Gordon Francis Sturmey,

Sutton Coldfield, England [73] Assignee: Joseph Lucas (industries) Limited,

Birmingham, England [22] Filed: Feb. 24, 1972 [21 1 Appl. No.: 228,885

[30] Foreign Application Priority Data Mar. 5, 1971 Great Britain 6220/71 [52] US. Cl 29/204, 29/200 A, 228/49 [51] Int. Cl. H0lm 35/18, 823p 19/00 [58] Field of Search 29/204, 203 D, 203 R, 208, 29/200 A, 204 D; 228/49 [451 Mar. 12, 1974 [56] References Cited UNITED STATES PATENTS 3,544,754 12/1970 Buttke 29/204 D X Primary Examiner-Thomas H. Eager Attorney, Agent, or FirmI-iolman & Stern 57 ABSTRACT An apparatus for welding a battery box lid to a battery box, employing a heater for melting portions of the lid between the filling tubes and around the lid. The heater is provided with bores receiving the filling tubes, the bores being substantially larger than the filling tubes and being undercut from the surface of the heater so that the filling tubes are not melted when the portions of the 'lid adjacent the filling tubes are melted.

7 Claims, 10 Drawing Figures PATENTED 3 795 963 sum 1 or 8 PATENTED 3. 795.963

sum 2 or 8 a Mr I I I I I II II I I I I I II I I I I Y I I I I I I I I I I I I I I I I I I ll I I I I I I I I I I I I W mu u PATENTEDHAR 1 21974 sum 3 or 8 QUE 4 WE UU PATENTEDMRIZIW' I 7 3,795,963

snmu'nra PATENTEI] HARI 21974 SHEET 5 OF 8 E y Mag/J M 49, Q OW Q A 49 FIG] PATENTEUHAR 1 21974 SHEET 6 BF 8 PATENTEI] MR! 2 I974 SHEET 8 OF 8 FIIL FIIL r1: r:|l FIIL F||L APPARATUS FOR USE IN THE MANUFACTURE OF ELECTRIC STORAGE BATTERIES This invention relates to apparatus for use in the manufacture of electric storage batteries.

Apparatus, according to the invention, includes a heater for melting the surface of a portion around a battery box lid to facilitate welding of the lid to a battery box, the heater being formed with a plurality of bores in which respective filling tubes extending from the lid are received when the lid engages the heater, said filling tubes providing access to the cell compartments respectively of the finished battery for the insertion of electrolyte, the dimensions of each'of said bores being substantially greater than the dimensions of its respective filling tube and part of the wall of each pore being undercut to the rear of the surface of the heater engaging said shoulder in use, the arrangement being such than when the lid engages the heater to melt said shoulder a portion of the lid adjacent each filling tube is engaged by said surface of the heater adjacent the undercut part of a respective bore and is melted thereby whereas each filling tube is spaced froom the wall of its respective bore and so remains unmelted.

Preferably, a portion of each undercut wall on the said surface of the heater is adapted to engage one of said portions of the lid which are each defined by an integral rib adapted to engage and seal with a cell partition wall in the battery box. I

Preferably, apparatus is adapted for use on a recessed lid and the heater is undercut to the rear of the surface of the heater which, in use, engages said portion around the lid so that a peripheral wall of the lid is not melted by the heater.

In the accompanying drawings, which illustrate the manufacture of a battery according to one example of the invention FIG. 1 illustrates a pack of battery plates and separators,

FIG. 2 shows a battery box with all but one of the packs in position,

FIG. 3 is a part sectional view of the battery box illustrating the completion of the intercell connections,

FIG. 4 is an inverted plan view of the battery lid,

FIG. 5 is a sectional view along line A-A in FIG. 4,

FIG. 6 is a partly diagrammatic side elevational view illustrating a machine used to connect the lid to the battery box,

FIG. 7 is a plan view of part of the heater of the machine shown in FIG. 6,

FIG. 8 is a side elevational view of part of the heater shown in FIG. 6,

FIG. 9 is a diagrammatic representation of the operation of the machine shown in FIG. 6, and

FIG. 10 is a side elevational view of part of the heater shown in FIG. 6 and also is a sectional view of the battery lid taken along the line B--B in FIG. 4 when the lid is partly engaged with the heater.

Referring first to FIGS. 1 to 3, a battery box 11 is moulded from polypropylene or other suitable thermoplastics material, the box including partition walls 12 dividing the box into six compartments. Each compartment receives a preformed pack 13 of positive and negative battery plates and separators. The two sets of plates in each of the four packs, which are to be mounted in the central compartments of the box 11 are connected respectively to conductive connecting lugs 15, 16 formed with extensions which, in use, extend substantially parallel to the partition walls 12. The extensions on the lugs 15 and 16 are each formed on their surfaces to be presented to the partition walls 12 with an upstanding annular rib 10 and each of the extensions on the lugs 16 is further formed on its surface to be presented to the respective partition wall with an outwardly extending spigot 164 (FIG. 3). The packs which are to be placed in the end compartments, each have one set of plates connected to a lug 15 or 16, and the other sets of plates connected respectively to the terminal posts 17 of the battery.

The partition walls 12 have holes stamped therein, and the arrangement is such that when the packs are positioned in the box 11, each spigot 16a passes through a hole in a respective partition wall and engages the lug 15 on a pack in the adjacent cell, the ribs 10 on each spigot 16a and each lug l5 surrounding the hole in the respective wall. The walls 12 are of course arranged to be sufficiently flexible to permit introduction of the packs into the compartments before the spigots 16a enter their respective holes. When all the packs are in position the required intercell connections are completed using a tool 18, as shown in FIG. 3. This tool includes a pair of electrodes 21, 22 which engage corresponding lugs 15, 16 respectively, and simultaneously exert pressure and pass current between the lugs 15, 16 so that the spigot 16a of each lug 16 becomes welded to the respective lug 15, and the hole in the respective partition wall 12 is sealed. When all the intercell connections are made the battery is complete apart from the lid.

The periphery of the open end of the box 11, and the free edges of the parition walls 12 lie in the same plane, and adjacent the open end of the box 11, the box 11 is formed with a peripheral outwardly extending shoulder 23. The outer surface of the wall of the box 11 between the shoulder 23 and the open end of the box 11 tapers inwardly, so that the outside dimensions of the open end of the box 11 are less than the outside dimensions of the box adjacent the shoulder, 23. Moreover, adjacent its closed end the longer walls of the box 11 are formed with respective recesses 24, clamping means (not shown) engaging the recesses 24, in use, and serving to mount the battery in position on a vehicle.

The lid 25 (FIGS. 4 and 5) is also moulded in polypropylene, or other suitable thermoplastics material,

7 and includes a peripheral'wall 26 which extends generally at right angles to the plane of the lid 25, and an internal peripheral shoulder 27 which is engaged by the free end of the wall of the box 11 when the lid 25 is in place closing the box 11. In addition, the lid is formed with partition walls 28, which, when the lid is in position on the box 11, engage the free edges of the partition walls 12 of the box 11, the walls 28 of the lid being thicker than the walls 12 of the box 11, to ensure that facial contact occurs between the free edges of the walls 12 and the walls 28. The lid 25 includes six, integral filling tubes 29, each of which has associated therewith avent passage 31, each tube 29 and respective vent passage 31 being associated with a respective cell of the battery when the lid 25 is in position on the box 11. In use, the lid 25 will have associated therewith, a manifold assembly, which is movable relative to the lid 25 between a first position wherein the vents 31 are open, and a second position wherein the vents 31 are closed. The vents 31 and the tubes 29 open into a common channel 32 in the lid 25, the channel 32 and the manifold assembly (not shown) facilitating simultaneous filling of the six cells of the battery to the desired level with electrolyte. The lid 25 further includes a pair of integral hollow spigots 33 which receive lead inserts for the terminal posts 17 respectively. At its opposite ends respectively the lid 25 includes a pair of integral guide pegs 30 which project from the lower surface of the lid 25 and present to the peripheral wall 26 an inclined surface extending from the wall 26. When the lid 25 is positioned on the box 11 the pegs 30 guide the lid into the correct longitudinal position relative to the box 1 1. Further guide pegs 30 are also provided on the partition walls 28 of the lid, the further guide pegs being provided on each partition wall 28 and serving to guide the walls 28 into engagement with their respective walls 12 when the lid is positioned on the box 11.

The lid 25 is welded to the box 11, and for this purpose the machine shown in FIG. 6 is used. The machine comprises a frame having a base 34, a pair of pedestals 35, and an arm 36, which extends at right angles to the pedestals 35, and which overlies the base 34. A first die part 37 is slidably mounted on the arm 36, for vertical movement relative to the arm 36. The die part 37 is carried on a pair of guide rods, one of which is shown at 38, and is moved vertically relative to the arm 36 by means ofa pneumatic or hydrualic ram 39. A conveyor (not shown) extends over the base 34, and the base 34 includes a platform 41 which is movable vertically, upwardly relative to the base 34, from a position wherein the platform is slightly below the plane of the conveyor. In use, the die part 37 supports a battery lid 25 and the platform 41 carries a battery box 11 which is to have the lid 25 welded thereto. Between the arm 36 and the base 34, the pedestals 35 support a pair of guideways, one of which is shown at 42, the guideways 42 extending parallel with the arms 36 and the base 34. Slidably mounted in the guideways 42 and movable along the guideways 42 by means of a pneumatic ram (not shown) is a heater assembly 43 (FIGS. 7, 8 and The heater assembly 43 includes a main body 44 carrying rollers (not shown) by means of which the heater assembly is slidably mounted in the guideways 42. The body 44 is also formed with passages within which electric heating elements are received. Secured to the face of the body 44, which is presented to the base 34, is a first aluminium alloy plate 45, and secured to the face of the body 44 presented to the arm 36 is a second aluminium alloy plate 46. The plate 46 is substantially the same size as the internal dimensions of the battery lid 25, but the periphery 47 of the plate 46 is undercutto the rear of the surface of the plate 46 to be presented tothe lid 25. In fact, the periphery 47 of the plate 46 defines first and second surfaces 47a, 47b respectively, the first surface 47a extending at right angles to the surface of the plate 46 to be presented to the lid and the second surface 47b extending from the surface 47a to the surface of the plate 46 adjacent the body 44 and being inclined inwardly with respect to the first surface 47a so as to define the undercut feature of the plate 46. Further, the plate 46 is provided with first and second sets of bores 48, 49 respectively arranged so that when the lid 25 is engaged with the heater assembly 43 the filling tubes 29 are received in the bores 48 respectively and the guide pegs and the terminal spigots 33 are received in the bores 49 respectively. Preferably the aluminium alloy used in the heater assembly 43 has the following composition: 3.5 4 percent copper, 0.4 0.7 percent magnesium, 0.4 0.7 percent maganese, and up to 0.7 percent silicon, the remainder being aluminium.

Referring now to FIG. 9, in addition to FIGS. 1 to 8, the sequence of operations when interconnecting the box 11 and the lid 25 is asfollows:

A series of boxes containing their respective interconnected packs 13, and having respective lids 25 placed thereon are fed onto the conveyor, and are carried by the conveyor between guiderails 53 singly over the platform 41. As a box 11 reaches the platform41 it engages a stop 52 supported by the pedestals 35, and in so doing operates a micro-switch which starts a cam control system. The cam control system firstly causes the platform 41 to be raised through the moving conveyor, thereby supporting and locating the box 11. Mechanical means (not shown) is now actuated to hold the box 11 firmly in position on the platform 41 for the remainder of the operation. The cam control system then causes the die part 37 to be lowered, until the die part 37 engages the lid 26 which is resting on top of the box 11'. When the die part 37 engages the lid 25, movemerit of the die part 37 and the platform 41 is stopped, and gripping means on the part 37 is actuated so that the lid 25 is gripped by the die part 37. The die'part 37 is then returned to its original position so that the lid 25 is lifted away from the box 11, and the platform 41 is lowered to a position a little above the moving conveyor. The heater assembly 43 is now moved along the guide ways 42 so that it occupies a position between the box 11 and the lid 25. The heater assembly 43 is maintained in a heated condition, so that the plate 46 and the plate 47 are both at 380 C. The die part 37 is then lowered, so that the plate 46 enters the lid 25 and engages the peripheral shoulder 27 and thefree edges of the walls 28 of the lid. One second after the lid 25 has engaged the heater the platform 41 is raised so that the free edge of the wall of the box 11 and the free edges of the partition walls 12 of the box 11 engage the plate 45 of the heater assembly 43. The box 11 and the lid 25 are then maintained in engagement with the heater for a further three seconds, so that the free edges of the wall of the box 11 and the partition walls12 are heated for three seconds, while the shoulder 27'and the free edges of the partition walls 28 are heated for a total of four seconds. The box 11 and the lid 25 are pressed lightly into contact with the heater assembly 43, and it will be appreciated that since the plate 46 is undercut at 47 (FIG. 8), then the wall 26 of the lid 25, will not be heated.

The die part 37 and the platform 41 are then returned to their previous positions and the heater assembly 43 is retracted from between the lid 25 and the box 11. When the heater assembly 43 is completely retracted, the platform 41 and the die part 37 are moved towards one another-to engage the lid 25 with the box 11. The time between the lid 25 and the box 11 leaving contact with the heater assembly 43 and contacting each other is approximately one and half seconds. The lid is then pressed firmly into contact with the box 11 for 4 seconds, during which time the areas of the box 11, and the lid 25, which were melted by contact with the heater assembly 43, merge together to seal the lid onto the box. After the lid has been held in contact with the box for 4 seconds,the lid is released from the die part 37, and the platform 41 islowered, so that the box l 1, together with the lid 25, which is welded thereto are returned to the conveyor, and are replaced by a further box 11, which is to have its respective lid welded to it. In addition, the die part 37 is returned to its original position in readiness for a further cycle. The overall cycle of the machine takes 12 seconds.

The apparatus described above is particularly designed for use with small battery boxes, that is boxes whose length is in the region of 170 mm. or less, the lids 25 being of course of a correspondingly small size. However, a problem exists in the sealing of a lid 25 to such a small battery box in that the reduced length of the lid 25 requires that each of the filling tubes 29 is positioned very close to an adjacent partition wall 28. Of course, the partition walls 28 of the lid are required to be melted by the heater plate 46 since in the finished battery the partition walls 28 are welded to the free edges of the partition walls 12 of the box 11. Thus, to melt the partition walls 28, a portion of the plate 46 must engage each of the partition walls 28 when the lid 25 is being heated which tends to cause the regions of the filling tubes 29 adjacent the partition walls 28 to be melted also, which clearly is unsatisfactory. Thus, as best shown in FIGS. 8 and 10, the first set of bores 48 in which the filling tubes 29 respectively are received, are arranged to be substantially larger than their respective filling tubes and further are arranged so that a part of the wall of each bore 48 is undercut to the rear of the surface of the plate 46 engaging the lid 25 in use. Then as shown in FIG. 10, when the lid 25 engages the heater assembly 43 each of the partition walls 28 is engaged by a portion of the surface of the plate 46 adjacent the undercut part of a respective bore 51 so as to be melted by the plate 46, but each filling tube 29 is arranged in its respective bore 48 so as to be spaced from the wall of its respective bore 48, whereby the filling tubes 29 remain unmelted during the engagement of the lid 25 with the heater assembly 43.

I claim:

1. Apparatus for use in the manufacture of electric storage batteries including a heater for melting the surface of a portion around a battery box lid to facilitate welding of the lid to a battery box, the heater being formed with a plurality of bores in which respective filling tubes extending from the lid are received when the than the dimensions of its respective filling tube and part of the wall of each bore being undercut to the rear of the surface of the heater engaging said shoulder in use, the arrangement being such that, when the lid engages the heater to melt said shoulder, a portion of the lid adjacent each filling tube is engaged by said surface of the heater adjacent the undercut part of a respective bore and is melted thereby whereas each filling tube is spaced from the wall of its respective bore and so remains unmelted.

2. An apparatus as claimed in claim 1, wherein a portion of each undercut wall on the said surface of the heater is adapted to engage one of said portions of the lid which are each defined by an integral rib adapted to engage and seal with a cell partition wall in the battery box.

3. An apparatus as claimed in claim 1, adapted for use on a recessed lidwherein the heater is undercut to the rear of the surface of the heater which, in use, engages said portion around the lid so that a peripheral wall of the lid is not melted by the heater.

4. An apparatus as claimed in claim 1, wherein at least the portion of the heater which defines said surface is formed of an aluminium alloy.

5. An apparatus as claimed in claim 4, wherein said aluminium alloy comprises 3.5 4 percent copper, 0.4 0.7 percent magnesium, 0 .4 0.7 percent manganese,

1 and upto 0.7 percent silicon, the remainder being alulid engages the heater, said filling tubes providing access to the cell compartments respectively of the finished battery for the insertion of electrolyte, the dimensions of each of said bores being substantially greater minium.

6. An apparatus as claimed in claim 1, wherein a further surface of the heater which is spacedparallel to said lid engaging surface is adapted to engage and melt a peripheral rim and exposed ends of partition walls in the battery box.

7. An apparatus as claimed in claim 1, further including conveyor means for transporting an unwelded assembly of battery box and lid towards a station at which said heater is located, means for gripping the lid at the station, means for supporting the battery box at the said station, means for effecting relative movement between said gripping means and supporting means so that, in use, the battery box/lid assembly is moved between a spaced apart position and an engaged position, and means for moving said heater between a position in which, in use, it is disposed between the battery box and the lid when separated and a position which allows the battery box and lid to be brought into engagement. 

1. Apparatus for use in the manufacture of electric storage batteries including a heater for melting the surface of a portion around a battery box lid to facilitate welding of the lid to a battery box, the heater being formed with a plurality of bores in which respective filling tubes extending from the lid are received when the lid engages the heater, said filling tubes providing access to the cell compartments respectively of the finished battery for the insertion of electrolyte, the dimensions of each of said bores being substantially greater than the dimensions of its respective filling tube and part of the wall of each bore being undercut to the rear of the surface of the heater engaging said shoulder in use, the arrangement being such that, when the lid engages the heater to melt said shoulder, a portion of the lid adjacent each filling tube is engaged by said surface of the heater adjacent the undercut part of a respective bore and is melted thereby whereas each filling tube is spaced from the wall of its respective bore and so remains unmelted.
 2. An apparatus as claimed in claim 1, wherein a portion of each undercut wall on the said surface of the heater is adapted to engage one of said portions of the lid which are each defined by an integral rib adapted to engage and seal with a cell partition wall in the battery box.
 3. An apparatus as claimed in claim 1, adapted for use on a recessed lid wherein the heater is undercut to the rear of the surface of the heater which, in use, engages said portion around the lid so that a peripheral wall of the lid is not melted by the heater.
 4. An apparatus as claimed in claim 1, wherein at least the portion of the heater which defines said surface is formed of an aluminium alloy.
 5. An apparatus as claimed in claim 4, wherein said aluminium alloy comprises 3.5 - 4 percent copper, 0.4 - 0.7 percent magnesium, 0.4 - 0.7 percent manganese, and up to 0.7 percent silicon, the remainder being aluminium.
 6. An apparatus as claimed in claim 1, wherein a further surface of the heater which is spaced parallel to said lid engaging surface is adapted to engage and melt a peripheral rim and exposed ends of partition walls in the battery box.
 7. An apparatus as claimed in claim 1, further including conveyor means for transporting an unwelded assembly of battery box and lid towards a station at which said heater is located, means for gripping the lid at the station, means for supporting the battery box at the said station, means for effecting relative movement between said gripping means and supporting means so that, in use, the battery box/lid assembly is moved between a spaced apart position and an engaged position, and means for moving said heater between a position in whIch, in use, it is disposed between the battery box and the lid when separated and a position which allows the battery box and lid to be brought into engagement. 